1. Field of the Invention
The present invention relates to a grommet. More particularly, the present invention relates to a grommet that is attached to an insertion hole formed in a panel (e.g., a vehicle body panel) in order to seal the insertion hole into which a pipe is inserted.
2. Description of Related Art
A known grommet of this type is taught by, for example, Japanese Laid-Open Patent Publication Number 2004-312927. As shown in FIGS. 7 to 11, the grommet 101 has a base 110 and boots 120. The base 110 is configured to be introduced into an insertion hole 142 formed in a panel 140. Each of the boots 120 is integrally formed in the base 110 and has a thinned wall thickness. The boots 120 are composed of truncated cone-shaped main portions 122 and connecting portions 124. The main portions 122 respectively have insertion bores 122a into which pipes 150 are inserted. The connecting portions 124 are respectively folded back from circumferential peripheries of the main portions 122 via folded back portions and are connected to the base 110. According to the grommet 101 thus constructed, the main portions 122 of the boots 120 can be flexibly displaced or moved relative to the base 110. Therefore, the insertion hole 142 can be reliably sealed even if the pipes 150 are not attached or positioned in place, i.e., even if there are variations in attaching positions of the pipes 150.
In order to attach the grommet 101 to the insertion hole 142 through which the pipes 150 are passed, the base 110 is pressed into the insertion hole 142 while the pipes 150 are respectively introduced into the insertion bores 122a of the main portions 122 of the boots 120. However, at this time, the folded back portions of the connecting portions 124 can be unfolded or stretched due to frictional forces produced between the pipes 150 and the insertion bores 122a or interference or contact of the main portions 122 with projected portions 152 that may be inherently formed in the pipes 150. As a result, as shown in FIG. 9, the grommet 101 can be attached to the insertion hole 142 while the main portions 122 can be projected from the base 110.
In such a case, an additional work connecting hoses (not shown) to end portions of the pipes 150 cannot be smoothly performed. Also, in such a case, the connecting portions 124 of the boots 120 are substantially fully stretched, so that movable ranges of the main portions 122 of the boots 120 relative to the base 110 can be limited. As a result, the panel insertion hole 142 of the panel 140 cannot be sufficiently sealed when the pipes 150 are moved or displaced relative to the panel 140.
Thus, as shown in FIGS. 10 and 11, it is necessary to move or return the main portions 122 projected from the base 110 into the base 110 by pressing down the same with user's fingers after the grommet 101 is attached to the insertion hole 142. This work is time-consuming. As a result, working efficiency of a grommet attaching operation can be reduced. Thus, there is a need in the art for an improved grommet.